Optical imaging system

ABSTRACT

An optical imaging system includes a reflective member having a reflective surface for changing an optical path of light, a first lens having positive refractive power, a second lens having negative refractive power, a third lens, a fourth lens, and a fifth lens. The first lens to the fifth lens are sequentially disposed along an optical axis from an object side and are each disposed closer to an image sensor than the reflective member. The optical imaging system satisfies 0.2 mm&lt;C1.0&lt;0.3 mm, where C1.0 is a distance by which the image sensor moves in a direction perpendicular to the optical axis with respect to a shake amount of 1.0° measured by a shake detection unit.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit under 35 USC 119(a) of Korean PatentApplication No. 10-2019-0112384 filed on Sep. 10, 2019 in the KoreanIntellectual Property Office, the entire disclosure of which isincorporated herein by reference for all purposes.

BACKGROUND 1. Field

The following description relates to an optical imaging system.

2. Description of Related Art

Cameras are used in portable electronic devices such as smartphones, andin accordance with the demand for the miniaturization of portableelectronic devices, miniaturization of cameras mounted in portableelectronic devices has also been required.

Furthermore, a telephoto camera has been adopted in portable electronicdevices to obtain a zoom effect for imaging a subject with a narrowangle of view.

However, when a plurality of lenses is disposed in the thicknessdirection of the portable electronic device, the thickness of theportable electronic device increases as the number of lenses increases,and thus, there is a problem in miniaturizing the portable electronicdevice.

In detail, since the telephoto camera has a relatively long focallength, there may be a problem that it may be difficult to apply to athin portable electronic device.

In addition, in the case of a camera having a shake correction function,a lens module including a plurality of lenses is generally moved. Inthis case, there is a problem in which power consumption may beincreased due to the weight of the lens module.

SUMMARY

This Summary is provided to introduce a selection of concepts insimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

An optical imaging system that may be mounted in a portable electronicdevice having a relatively reduced thickness and has a relatively longfocal length.

In one general aspect, an optical imaging system includes a reflectivemember having a reflective surface to change an optical path of light, afirst lens having positive refractive power, a second lens havingnegative refractive power, a third lens, a fourth lens, and a fifthlens. The first lens to the fifth lens are sequentially disposed alongan optical axis from an object side and are each disposed closer to animage sensor than the reflective member. The optical imaging systemsatisfies 0.2 mm<C1.0<0.3 mm, where C1.0 is a distance by which theimage sensor moves in a direction perpendicular to the optical axis withrespect to a shake amount of 1.0° measured by a shake detection unit.

The optical imaging system may satisfy 0.1<L1S1/f<1, where L1S1 is aradius of curvature of an object-side surface of the first lens and f isa total focal length of the optical imaging system.

The optical imaging system may satisfy−2.0<(L1S1+L1S2)/(L1S1−L1S2)<−0.1, where L1S2 is a radius of curvatureof an image-side surface of the first lens.

The optical imaging system may satisfy −2.0<L3S2/f<−0.1, where L3S2 is aradius of curvature of an image-side surface of the third lens and f isa total focal length of the optical imaging system.

The optical imaging system may satisfy−20.0<(L3S1+L3S2)/(L3S1−L3S2)<−0.1, where L3S1 is a radius of curvatureof an object-side surface of the third lens.

The optical imaging system may satisfy 0.1<f/f1<5.0, where f is a totalfocal length of the optical imaging system and f1 is a focal length ofthe first lens.

The optical imaging system may satisfy −1.0 21 f/f3<−0.1, where f is atotal focal length of the optical imaging system and f3 is a focallength of the third lens.

The optical imaging system may satisfy −1.0<f/f4<−0.1, where f is atotal focal length of an optical system and f4 is a focal length of thefourth lens.

The optical imaging system may satisfy 0.1<f/f5<2.0, where f is a totalfocal length of an optical system and f5 is a focal length of the fifthlens.

The optical imaging system may satisfy 0.5<BFL/TTL<0.7, where TTL is adistance from an object-side surface of the first lens to an imagingplane of the image sensor on the optical axis, and BFL is a distancefrom an image-side surface of the fifth lens to the imaging plane of theimage sensor on the optical axis.

The optical imaging system may satisfy 1.8<TTL/(2*IMG HT)<2.2, where TTLis a distance from an object-side surface of the first lens to animaging plane of the image sensor on the optical axis, and IMG HT ishalf of a diagonal length of the imaging plane of the image sensor.

The optical imaging system may satisfy 0.8<TTL/f<1.1, where TTL is adistance from an object-side surface of the first lens to an imagingplane of the image sensor on the optical axis, and f is a total focallength of the optical imaging system.

The optical imaging system may satisfy f1/|f23|<1.0, where f1 is a focallength of the first lens and f23 is a combined focal length of thesecond lens and the third lens.

The optical imaging system may satisfy 0.1 mm<C0.5<0.2 mm, where C0.5 isa distance by which the image sensor moves in the directionperpendicular to the optical axis with respect to an amount of shake of0.5° measured by the shake detection unit.

The optical imaging system may satisfy 0.35 mm<C1.5<0.45 mm, where C1.5is a distance by which the image sensor moves in the directionperpendicular to the optical axis with respect to an amount of shake of1.5° measured by the shake detection unit.

The optical imaging system may satisfy 0.5 mm<C2.0<0.6 mm, where C2.0 isa distance by which the image sensor moves in the directionperpendicular to the optical axis with respect to an amount of shake of2.0° measured by the shake detection unit.

In another general aspect, an optical imaging system includes areflective member to change an optical path of light, a first lens, asecond lens, a third lens, a fourth lens, a fifth lens, an image sensor,and a shake detection unit to measure an amount of shake of the opticalimaging system when capturing an image. The first lens to the fifth lensare sequentially disposed along an optical axis from an object side andare each disposed between the image sensor and the reflective memberalong the optical axis. The optical imaging system satisfies 0.13mm<C<0.523 mm, where C is a distance by which the image sensor moves ina direction perpendicular to the optical axis in a case in which theamount of shake measured by the shake detection unit is between 0.5° and2.0° inclusive.

Other features and aspects will be apparent from the following detaileddescription, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram of an optical imaging system accordingto a first example.

FIG. 2 is a curve illustrating aberration characteristics of the opticalimaging system illustrated in FIG. 1.

FIG. 3 is a configuration diagram of an optical imaging system accordingto a second example.

FIG. 4 is a curve illustrating aberration characteristics of the opticalimaging system illustrated in FIG. 3.

FIG. 5 is a configuration diagram of an optical imaging system accordingto a third example.

FIG. 6 is a curve illustrating aberration characteristics of the opticalimaging system illustrated in FIG. 5.

Throughout the drawings and the detailed description, the same referencenumerals refer to the same elements. The drawings may not be to scale,and the relative size, proportions, and depiction of elements in thedrawings may be exaggerated for clarity, illustration, and convenience.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the methods, apparatuses,and/or systems described herein. However, various changes,modifications, and equivalents of the methods, apparatuses, and/orsystems described herein will be apparent to one of ordinary skill inthe art. The sequences of operations described herein are merelyexamples, and are not limited to those set forth herein, but may bechanged as will be apparent to one of ordinary skill in the art, withthe exception of operations necessarily occurring in a certain order.Also, descriptions of functions and constructions that would be wellknown to one of ordinary skill in the art may be omitted for increasedclarity and conciseness.

The features described herein may be embodied in different forms, andare not to be construed as being limited to the examples describedherein. Rather, the examples described herein have been provided so thatthis disclosure will be thorough and complete, and will fully convey thescope of the disclosure to one of ordinary skill in the art.

Herein, it is noted that use of the term “may” with respect to anexample or embodiment, e.g., as to what an example or embodiment mayinclude or implement, means that at least one example or embodimentexists in which such a feature is included or implemented while allexamples and embodiments are not limited thereto.

Throughout the specification, when an element, such as a layer, region,or substrate, is described as being “on,” “connected to,” or “coupledto” another element, it may be directly “on,” “connected to,” or“coupled to” the other element, or there may be one or more otherelements intervening therebetween. In contrast, when an element isdescribed as being “directly on,” “directly connected to,” or “directlycoupled to” another element, there can be no other elements interveningtherebetween.

As used herein, the term “and/or” includes any one and any combinationof any two or more of the associated listed items.

Although terms such as “first,” “second,” and “third” may be used hereinto describe various members, components, regions, layers, or sections,these members, components, regions, layers, or sections are not to belimited by these terms. Rather, these terms are only used to distinguishone member, component, region, layer, or section from another member,component, region, layer, or section. Thus, a first member, component,region, layer, or section referred to in examples described herein mayalso be referred to as a second member, component, region, layer, orsection without departing from the teachings of the examples.

Spatially relative terms such as “above,” “upper,” “below,” and “lower”may be used herein for ease of description to describe one element'srelationship to another element as illustrated in the figures. Suchspatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, an element described as being “above” or “upper”relative to another element will then be “below” or “lower” relative tothe other element. Thus, the term “above” encompasses both the above andbelow orientations depending on the spatial orientation of the device.The device may also be oriented in other ways (for example, rotated 90degrees or at other orientations), and the spatially relative terms usedherein are to be interpreted accordingly.

The terminology used herein is for describing various examples only, andis not to be used to limit the disclosure. The articles “a,” “an,” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. The terms “comprises,” “includes,”and “has” specify the presence of stated features, numbers, operations,members, elements, and/or combinations thereof, but do not preclude thepresence or addition of one or more other features, numbers, operations,members, elements, and/or combinations thereof.

Due to manufacturing techniques and/or tolerances, variations of theshapes illustrated in the drawings may occur. Thus, the examplesdescribed herein are not limited to the specific shapes illustrated inthe drawings, but include changes in shape that occur duringmanufacturing.

The features of the examples described herein may be combined in variousways as will be apparent after an understanding of the disclosure ofthis application. Further, although the examples described herein have avariety of configurations, other configurations are possible as will beapparent after an understanding of the disclosure of this application.

The drawings may not be to scale, and the relative sizes, proportions,and depiction of elements in the drawings may be exaggerated forclarity, illustration, and convenience.

In the following lens configuration diagram, the thickness, size, andshape of the lens are illustrated to be somewhat exaggerated forexplanation. In particular, the shape of the spherical or asphericalsurface presented in the lens configuration diagram is provided as anexample, and the shape of the spherical or aspherical surface is notlimited thereto.

An optical imaging system according to an example may include aplurality of lenses disposed along an optical axis. The plurality oflenses may be spaced apart from each other by a predetermined distancealong the optical axis.

As an example, the optical imaging system may include five lenses.

A first lens refers to a lens closest to an object side (or a reflectivemember), and a fifth lens refers to a lens closest to an image sensor.

Further, in each lens, a first surface means a surface close to theobject side (or an object side surface), and a second surface means asurface close to the image side (or an image side surface). In addition,in this specification, the numerical values for radii of curvature,thickness, etc. of the lens are all in mm, and the unit of anglemeasurement is degrees.

In addition, in the description of the shape of each lens, the meaningthat one surface is convex indicates that the paraxial region portion ofthe surface is convex, and the meaning that one surface is concaveindicates that the paraxial region portion of the surface is concave.

The paraxial region refers to a relatively narrow region near theoptical axis.

The optical imaging system according to an example includes five lenses.

For example, the optical imaging system includes a first lens, a secondlens, a third lens, a fourth lens, and a fifth lens arranged in orderfrom the object side.

However, the optical imaging system according to the example is not onlycomprised of five lenses, and may further include other components.

For example, the optical imaging system may further include a reflectivemember having a reflective surface that changes an optical path. Forexample, the reflective member may be a mirror or a prism.

The reflective member is disposed closer to the object side than theplurality of lenses. For example, the reflective member may be disposedcloser to the object side than the first lens. Therefore, the lensdisposed closest to the object side may be a lens disposed closest tothe reflective member.

Light incident on the reflective member may be curved to be directed tothe first to fifth lenses.

In addition, the optical imaging system may further include an imagesensor for converting an incident image of the object into an electricalsignal.

In addition, the optical imaging system may further include an infraredblocking filter (hereinafter, referred to as a ‘filter’) for blockinginfrared light. The filter is disposed between the lens (the fifth lens)disposed closest to the image sensor and the image sensor.

All lenses constituting the optical imaging system according to anexample may be formed of a plastic material.

The optical imaging system according to an example is configured in sucha manner that the image sensor may be moved to correct shake of animage. As an example, the image sensor of the optical imaging systemaccording to an example may be moved in a direction perpendicular to theoptical axis.

For example, when shake occurs due to user hand-shake or the like whenan image is captured, the shake may be corrected by applying a relativedisplacement corresponding to the shake to the image sensor.

Although not illustrated in the drawings, a shake correction unit may beprovided to move the image sensor, and the shake correction unit mayinclude a VCM actuator using a magnet and a coil.

The image sensor of the optical imaging system may be moved in adirection perpendicular to the optical axis, based on a detection signalfrom a shake detection unit (e.g., a gyro sensor).

Each of the plurality of lenses may have at least one asphericalsurface.

For example, at least one of the first and second surfaces of the firstto fifth lenses may be aspherical. In this case, the aspherical surfacesof the first to fifth lenses are expressed by Equation 1.

$\begin{matrix}{Z = {\frac{{cY}^{2}}{1 + \sqrt{1 - {\left( {1 + K} \right)c^{2}Y^{2}}}} + {AY}^{4} + {BY}^{6} + {CY}^{8} + {DY}^{10} + {EY}^{12}}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

In Equation 1, c is the curvature of the lens (a reciprocal of theradius of curvature), K is a conic constant, and Y represents a distancefrom any point on an aspherical surface of the lens to an optical axis.In addition, constants A to E indicate aspheric coefficients. Zrepresents a distance (SAG) from any point on an aspherical surface ofthe lens to a vertex of the aspherical surface.

The optical imaging system according to an example may satisfy at leastone of the following conditional expressions.

-   -   Conditional Expression 1: 0.1 mm<C0.5<0.2 mm    -   Conditional Expression 2: 0.2 mm<C1.0<0.3 mm    -   Conditional Expression 3: 0.35 mm<C1.5<0.45 mm    -   Conditional Expression 4: 0.5 mm<C2.0<0.6 mm    -   Conditional Expression 5: 0.1<L1S1/f<1    -   Conditional Expression 6: −2.0<(L1S1+L1S2)/(L1S1-L1S2)<−0.1    -   Conditional Expression 7: −2.0<L3S2/f<−0.1    -   Conditional Expression 8: −20.0<(L3S1+L3S2)/(L3S1-L3S2)<−0.1    -   Conditional Expression 9: 0.1<f/f1<5.0    -   Conditional Expression 10: −1.0<f/f3<−0.1    -   Conditional Expression 11: −1.0<f/f4<−0.1    -   Conditional Expression 12: 0.1<f/f5<2.0    -   Conditional Expression 13: 0.5<BFL/TTL<0.7    -   Conditional Expression 14: 1.8<TTL/(2*IMG HT)<2.2    -   Conditional Expression 15: 0.8<TTL/f<1.1    -   Conditional Expression 16: f1/|f23|<1.0

In the conditional expressions, C0.5 is a moving distance of the imagesensor with respect to a shake amount of 0.5°, C1.0 is a moving distanceof the image sensor with respect to a shake amount of 1.0°, C1.5 is amoving distance of the image sensor with respect to a shake amount of1.5°, and C2.0 is a moving distance of the image sensor with respect toa shake amount of 2.0°.

In this case, the shake amount may be an amount of shake of an imagemeasured by the shake detection unit (for example, a gyro sensor), andthe moving distance of the image sensor may indicate a moving distancein a direction perpendicular to the optical axis.

In the conditional expressions, L1S1 is a radius of curvature of theobject-side surface of the first lens, L1S2 is a radius of curvature ofthe image-side surface of the first lens, L3S1 is a radius of curvatureof the object-side surface of the third lens, and L3S2 is a radius ofcurvature of the image side-surface of the third lens.

In the conditional expressions, f1 is a focal length of the first lens,f3 is a focal length of the third lens, f4 is a focal length of thefourth lens, f5 is a focal length of the fifth lens, f23 is a combinedfocal length of the second and third lenses, and f is a total focallength of the optical imaging system.

In the conditional expressions, BFL is a distance from the image-sidesurface of the fifth lens to the imaging plane of the image sensor onthe optical axis, and TTL is a distance from the object-side surface ofthe first lens to the imaging plane of the image sensor on the opticalaxis.

In the conditional expressions, IMG HT is half a diagonal length of theimaging plane of the image sensor.

Next, first to fifth lenses constituting the optical imaging systemaccording to an example will be described.

The first lens has positive refractive power. In addition, both surfacesof the first lens may be convex. In detail, the first surface and thesecond surface of the first lens may be convex.

In the first lens, at least one surface of the first surface and thesecond surface may be aspherical. For example, both surfaces of thefirst lens may be aspherical.

The second lens has negative refractive power. In addition, the secondlens may have a meniscus shape convex toward the object. In other words,the first surface of the second lens may be convex, and the secondsurface of the second lens may be concave.

In the second lens, at least one surface of the first surface and thesecond surface may be aspherical. For example, both surfaces of thesecond lens may be aspherical.

The third lens has negative refractive power. In addition, the thirdlens may have a meniscus shape convex toward the image side. In detail,the first surface of the third lens may be concave, and the secondsurface of the third lens may be convex.

In the third lens, at least one surface of the first surface and thesecond surface may be aspherical. For example, both surfaces of thethird lens may be aspherical.

The fourth lens has negative refractive power. In addition, the fourthlens may have a meniscus shape convex toward the image side. In detail,the first surface of the fourth lens may be concave, and the secondsurface of the fourth lens may be convex.

In the fourth lens, at least one surface of the first surface and thesecond surface may be aspherical. For example, both surfaces of thefourth lens may be aspherical.

The fifth lens has positive refractive power. In addition, the fifthlens may have a meniscus shape convex toward the object. In detail, thefirst surface of the fifth lens may be convex, and the second surface ofthe fifth lens may be concave.

In the fifth lens, at least one surface of the first surface and thesecond surface may be aspherical. For example, both surfaces of thefifth lens may be aspherical.

Among the first to fifth lenses, the first lens has an absolute value ofa smallest focal length.

Among the first to fifth lenses, the third lens has an absolute value ofa greatest focal length.

A combined focal length of the second lens and the third lens has avalue less than 0 (e.g., negative refractive power). The second lens andthe third lens each have negative refractive power, but the example isnot limited thereto. For example, the third lens may have positiverefractive power in a range in which the combined focal length of thesecond lens and the third lens has a value less than zero.

The optical imaging system according to an example has a feature of atelephoto lens having a relatively narrow angle of view and a relativelylong focal length.

An optical imaging system according to a first example will be describedwith reference to FIGS. 1 and 2.

An optical system according to the first example includes a first lens110, a second lens 120, a third lens 130, a fourth lens 140, and a fifthlens 150, and may further include a filter 160 and an image sensor 170.

The optical imaging system may further include a reflective member Rdisposed closer to the object side than the first lens 110 and having areflective surface changing an optical path. In the first example, thereflective member R may be a prism, or may also be provided as a mirror.

Lens characteristics of respective lenses, for example, radii ofcurvature, thicknesses of lens or distances between lenses, refractiveindices, Abbe numbers, focal lengths, are as illustrated in Table 1.

TABLE 1 Surface Curvature Thickness or Refractive Abbe Focal NumberRemark Radius Distance Index number Length S1 Prism Infinity 2.6 1.71729.5 S2 Infinity 2.6 1.717 29.5 S3 Infinity 2.2 S4 First 4.44597 1.81.535 560 7.7108 Lens S5 −49.12118 0.04 S6 Second 7.64035 1.06636 1.61525.9 −9.2765 Lens S7 3.0926 1.2 S8 Third −4.29081 0.47 1.6397 23.5−88.7246 Lens S9 −4.84008 0.5 S10 Fourth −3.59392 0.85 1.615 25.9−53.0231 Lens S11 −4.40285 0.04 S12 Fifth 3.64359 0.87926 1.535 56019.2670 Lens S13 5.16167 8.07395 S14 Filter Infinity 0.14993 1.516 64.1S15 Infinity 0.92974 S16 Imaging Infinity Plane

A total focal length f of the optical imaging system according to thefirst example is 15 mm, BFL is 9.154 mm, TTL is 15.999 mm, and IMG HT is4.2 mm.

A combined focal length f23 of the second lens 120 and the third lens130 is −8.6322 mm.

In the first example, the first lens 110 has positive refractive power,and the first and second surfaces of the first lens 110 are convex.

The second lens 120 has negative refractive power, the first surface ofthe second lens 120 is convex, and the second surface of the second lens120 is concave.

The third lens 130 has negative refractive power, the first surface ofthe third lens 130 is concave, and the second surface of the third lens130 is convex.

The fourth lens 140 has negative refractive power, the first surface ofthe fourth lens 140 is concave, and the second surface of the fourthlens 140 is convex.

The fifth lens 150 has positive refractive power, the first surface ofthe fifth lens 150 is convex, and the second surface of the fifth lens150 is concave.

Each surface of the first lens 110 to the fifth lens 150 has anaspherical surface coefficient as illustrated in Table 2. For example,both the object-side surface and the image-side surface of the firstlens 110 to the fifth lens 150 are aspherical surfaces.

TABLE 2 K A B C D E S4 −0.640837 0.0008149 1.99E−05 2.22E−06 −7.07E−07 0 S5 0 0.0005221 −3.30E−05  −1.51E−05  1.22E−06 0 S6 0 −3.04E−03−1.97E−05  6.01E−07 1.07E−06 0 S7 0 −0.00384   −2.32E−04  5.63E−05−4.94E−06  0 S8 0  4.90E−03 1.65E−03 −5.70E−04  6.23E−05 0 S9 0−1.91E−03  0.0039516 −0.001312 1.69E−04 −7.99E−06 S10 0  1.05E−02−0.000387 −0.000487 1.06E−04 −9.43E−06 S11 −2.50E+00  5.51E−04 −0.0003763.45E−05 2.06E−06 −7.74E−07 S12 0 −1.45E−02 1.54E−03 −8.75E−05  2.50E−07 8.26E−08 S13 0 −7.22E−03 4.71E−04 4.30E−05 −6.63E−06   3.06E−07

In addition, the optical imaging system configured as described abovemay have aberration characteristics illustrated in FIG. 2.

An optical imaging system according to a second example will bedescribed with reference to FIGS. 3 and 4.

The optical imaging system according to the second example includes afirst lens 210, a second lens 220, a third lens 230, a fourth lens 240,and a fifth lens 250, and may further include a filter 260 and an imagesensor 270.

The optical imaging system may further include a reflective member Rdisposed closer to the object side than the first lens 210 and having areflective surface changing an optical path. In the second example, thereflective member R may be a prism, or may also be provided as a mirror.

Lens characteristics of each lens, for example, a radius of curvature, athickness of lens or a distance between lenses, a refractive index, Abbenumber, and a focal length are illustrated in Table 3.

TABLE 3 Surface Curvature Thickness or Refractive Abbe Focal NumberRemark Radius Distance Index number Length S1 Prism Infinity 2.6 1.71729.5 S2 Infinity 2.6 1.717 29.5 S3 Infinity 2.2 S4 First 4.51189 1.807141.535 560 7.9179 Lens S5 −59.62357 0.04 S6 Second 7.97843 0.98732 1.61525.9 −10.1740 Lens S7 3.34157 1.12724 S8 Third −6.7276 0.48137 1.639723.5 −72.7400 Lens S9 −8.08422 0.55656 S10 Fourth −3.3 1.0333 1.615 25.9−35.5665 Lens S11 −4.34972 0.04 S12 Fifth 3.52947 1.29659 1.535 56016.9720 Lens S13 5.03452 7.95097 S14 Filter Infinity 0.11 1.516 64.1 S15Infinity 0.84142 S16 Imaging Infinity Plane

The total focal length f of the optical imaging system according to thesecond example is 15 mm, BFL is 8.902 mm, TTL is 16.235 mm, and IMG HTis 4.0 mm.

In the second example, the first lens 210 has positive refractive power,and the first and second surfaces of the first lens 210 are convex.

The second lens 220 has negative refractive power, the first surface ofthe second lens 220 is convex, and the second surface of the second lens220 is concave.

The third lens 230 has negative refractive power, the first surface ofthe third lens 230 is concave, and the second surface of the third lens230 is convex.

The fourth lens 240 has negative refractive power, the first surface ofthe fourth lens 240 is concave, and the second surface of the fourthlens 240 is convex.

The fifth lens 250 has positive refractive power, the first surface ofthe fifth lens 250 is convex, and the second surface of the fifth lens250 is concave.

Each surface of the first lens 210 to the fifth lens 250 has anaspherical surface coefficient as illustrated in Table 4. For example,both the object-side surface and the image-side surface of the firstlens 210 to the fifth lens 250 are aspherical surfaces.

TABLE 4 K A B C D E S4 −0.614611  0.0008302 2.31E−05  2.55E−06−2.80E−07   4.24E−09 S5 0 −0.000139 2.77E−05 −8.77E−06 7.67E−07−3.37E−08 S6 0 −3.48E−03 −9.51E−05   9.42E−06 −6.55E−07  0 S7 0−0.00284  −2.38E−04   5.67E−05 −1.00E−05  0 S8 0  3.82E−03 1.96E−03−4.12E−04 2.66E−05 0 S9 0 −1.33E−03  0.0030535 −0.00092 1.02E−04−8.44E−06 S10 0  1.60E−02 −0.002941   0.0001628 3.00E−05 −9.49E−06 S11−2.66E+00  9.28E−04 −0.000862  1.69E−04 −7.43E−06  −1.37E−07 S12 0−1.38E−02 1.43E−03 −9.04E−05 4.22E−06 −2.46E−07 S13 0 −5.87E−03 5.04E−04−2.04E−05 5.58E−06 −3.39E−07

In addition, the optical imaging system configured as described abovemay have aberration characteristics illustrated in FIG. 4.

An optical imaging system according to a third example will be describedwith reference to FIGS. 5 and 6.

The optical imaging system according to the third example includes afirst lens 310, a second lens 320, a third lens 330, a fourth lens 340,and a fifth lens 350, and may further include a filter 360 and an imagesensor 370.

The optical imaging system may further include a reflective member Rdisposed closer to the object side than the first lens 310 and having areflective surface changing an optical path. In the third example, thereflective member R may be a prism, or may also be provided as a mirror.

The lens characteristics of each lens, for example, a radius ofcurvature, a thickness of lens or a distance between lenses, arefractive index, Abbe number, and a focal length are illustrated inTable 5.

TABLE 5 Surface Curvature Thickness or Refractive Abbe Focal NumberRemark Radius Distance Index number Length S1 Prism Infinity 2.6 1.71729.5 S2 Infinity 2.6 1.717 29.5 S3 Infinity 2.2 S4 First 4.58468 1.840361.535 560 8.0553 Lens S5 −61.77669 0.04 S6 Second 8.09869 1.06664 1.61525.9 −9.8933 Lens S7 3.3 1.08808 S8 Third −15.94159 0.48997 1.6397 23.590.6914 Lens S9 −22.24539 0.65863 S10 Fourth −3.3 1.05572 1.615 25.943.5018 Lens S11 −4.22291 0.04 S12 Fifth 3.61122 1.38832 1.535 56018.0224 Lens S13 5 7.71747 S14 Filter Infinity 0.11 1.516 64.1 S15Infinity 0.73967 S16 Imaging Infinity Plane

The total focal length f of the optical imaging system according to thethird example is 15 mm, BFL is 8.567 mm, TTL is 16.235 mm, and IMG HT is4.2 mm.

In the third example, the first lens 310 has positive refractive power,and the first and second surfaces of the first lens 310 are convex.

The second lens 320 has negative refractive power, the first surface ofthe second lens 320 is convex, and the second surface of the second lens320 is concave.

The third lens 330 has negative refractive power, the first surface ofthe third lens 330 is concave, and the second surface of the third lens330 is convex.

The fourth lens 340 has negative refractive power, the first surface ofthe fourth lens 340 is concave, and the second surface of the fourthlens 340 is convex.

The fifth lens 350 has positive refractive power, the first surface ofthe fifth lens 350 is convex, and the second surface of the fifth lens350 is concave.

Each surface of the first lens 310 to the fifth lens 350 has anaspherical surface coefficient as illustrated in Table 6. For example,both the object-side surface and the image-side surface of the firstlens 310 to the fifth lens 350 are aspherical surfaces.

TABLE 6 K A B C D E S4 −0.632149  0.0008137 7.83E−06 4.60E−06 −4.53E−07 3.71E−09 S5 0 −0.000197 3.55E−05 −1.04E−05   8.25E−07 −3.54E−08 S6 0−3.65E−03 −5.31E−05  7.20E−06 −4.57E−07 0 S7 0 −0.003515 6.96E−061.74E−05 −2.81E−06 0 S8 0  2.46E−03 2.80E−03 −6.76E−04   6.11E−05 0 S9 0−1.26E−03  0.0036059 −0.001124  1.04E−04 −6.92E−06 S10 0  1.70E−02−0.003299  0.0004748 −7.03E−05 −1.05E−06 S11 −3.02E+00 −3.33E−04−0.00015  1.02E−04 −1.18E−05  1.14E−06 S12 0 −1.40E−02 1.99E−03−1.68E−04   8.16E−06 −1.78E−07 S13 0 −6.56E−03 5.30E−04 5.37E−05−1.01E−05  8.18E−07

In addition, the optical imaging system configured as described abovemay have aberration characteristics illustrated in FIG. 6.

TABLE 7 Moving Distance of Image Shake amount Sensor 0.5 degree 0.130 mm1.0 degree 0.261 mm 1.5 degrees 0.392 mm 2.0 degrees 0.523 mm

Table 7 illustrates the moving distance of the image sensor depending onthe measured amount of shake in the optical imaging system according tothe first to third examples.

As set forth above, an optical imaging system according to an examplemay be mounted in a portable electronic device having a relativelyreduced thickness, and may have a long focal length.

While this disclosure includes specific examples, it will be apparent toone of ordinary skill in the art that various changes in form anddetails may be made in these examples without departing from the spiritand scope of the claims and their equivalents. The examples describedherein are to be considered in a descriptive sense only, and not forpurposes of limitation. Descriptions of features or aspects in eachexample are to be considered as being applicable to similar features oraspects in other examples. Suitable results may be achieved if thedescribed techniques are performed to have a different order, and/or ifcomponents in a described system, architecture, device, or circuit arecombined in a different manner, and/or replaced or supplemented by othercomponents or their equivalents. Therefore, the scope of the disclosureis defined not by the detailed description, but by the claims and theirequivalents, and all variations within the scope of the claims and theirequivalents are to be construed as being included in the disclosure.

What is claimed is:
 1. An optical imaging system comprising: areflective member comprising a reflective surface configured to changean optical path of light; a first lens having positive refractive power;a second lens having negative refractive power; a third lens; a fourthlens; and a fifth lens, wherein the first lens to the fifth lens aresequentially disposed along an optical axis from an object side and areeach disposed closer to an image sensor than the reflective member, andwherein 0.2 mm<C1.0<0.3 mm, where C1.0 is a distance by which the imagesensor moves in a direction perpendicular to the optical axis withrespect to an amount of shake of 1.0° measured by a shake detectionunit.
 2. The optical imaging system of claim 1, wherein 0.1<L1S1/f<1,where L1S1 is a radius of curvature of an object-side surface of thefirst lens and f is a total focal length of the optical imaging system.3. The optical imaging system of claim 2, wherein−2.0<(L1S1+L1S2)/(L1S1−L1S2) <−0.1, where L1S2 is a radius of curvatureof an image-side surface of the first lens.
 4. The optical imagingsystem of claim 1, wherein −2.0<L3S2/f<−0.1, where L3S2 is a radius ofcurvature of an image-side surface of the third lens and f is a totalfocal length of the optical imaging system.
 5. The optical imagingsystem of claim 4, wherein −20.0<(L3S1+L3S2)/(L3S1−L3S2)<−0.1, whereL3S1 is a radius of curvature of an object-side surface of the thirdlens.
 6. The optical imaging system of claim 1, wherein 0.1<f/f1<5.0,where f is a total focal length of the optical imaging system and f1 isa focal length of the first lens.
 7. The optical imaging system of claim1, wherein −1.0<f/f3<−0.1, where f is a total focal length of theoptical imaging system and f3 is a focal length of the third lens. 8.The optical imaging system of claim 1, wherein −1.0<f/f4<−0.1, where fis a total focal length of an optical system and f4 is a focal length ofthe fourth lens.
 9. The optical imaging system of claim 1, wherein0.1<f/f5<2.0, where f is a total focal length of an optical system andf5 is a focal length of the fifth lens.
 10. The optical imaging systemof claim 1, wherein 0.5<BFL/TTL<0.7, where TTL is a distance from anobject-side surface of the first lens to an imaging plane of the imagesensor on the optical axis, and BFL is a distance from an image-sidesurface of the fifth lens to the imaging plane of the image sensor onthe optical axis.
 11. The optical imaging system of claim 1, wherein1.8<TTL/(2*IMG HT)<2.2, where TTL is a distance from an object-sidesurface of the first lens to an imaging plane of the image sensor on theoptical axis, and IMG HT is half of a diagonal length of the imagingplane of the image sensor.
 12. The optical imaging system of claim 1,wherein 0.8<TTL/f<1.1, where TTL is a distance from an object-sidesurface of the first lens to an imaging plane of the image sensor on theoptical axis, and f is a total focal length of the optical imagingsystem.
 13. The optical imaging system of claim 1, wherein f1/|f23|<1.0,where f1 is a focal length of the first lens and f23 is a combined focallength of the second lens and the third lens.
 14. The optical imagingsystem of claim 1, wherein 0.1 mm<C0.5<0.2 mm, where C0.5 is a distanceby which the image sensor moves in the direction perpendicular to theoptical axis with respect to an amount of shake of 0.5° measured by theshake detection unit.
 15. The optical imaging system of claim 1, wherein0.35 mm<C1.5<0.45 mm, where C1.5 is a distance by which the image sensormoves in the direction perpendicular to the optical axis with respect toan amount of shake of 1.5° measured by the shake detection unit.
 16. Theoptical imaging system of claim 1, wherein 0.5 mm<C2.0<0.6 mm, whereC2.0 is a distance by which the image sensor moves in the directionperpendicular to the optical axis with respect to an amount of shake of2.0° measured by the shake detection unit.
 17. An optical imaging systemcomprising: a reflective member configured to change an optical path oflight; a first lens; a second lens; a third lens; a fourth lens; a fifthlens; an image sensor; and a shake detection unit configured to measurean amount of shake of the optical imaging system when capturing animage, wherein the first lens to the fifth lens are sequentiallydisposed along an optical axis from an object side and are each disposedbetween the image sensor and the reflective member along the opticalaxis, and wherein 0.13 mm<C<0.523 mm, where C is a distance by which theimage sensor moves in a direction perpendicular to the optical axis in acase in which the amount of shake measured by the shake detection unitis between 0.5° and 2.0° inclusive.